A ban on plastic bags used by grocers and retailers can negatively impact sales in the ban area and increase sales among stores just outside the ban region, according to a new study from the National Center for Policy Analysis (NCPA).

The NCPA surveyed store managers in Los Angeles County where a ban of thin-film bags took effect in July, 2011, to determine the ban’s impact on revenues and employment.

Over a 1 year period before and after the ban, stores that fell under the bag ban experienced a 10 percent reduction in employment, while employment in stores outside of the ban slightly increased.

Additionally, the majority of stores surveyed in areas with a ban reported an overall average sales decline of nearly six percent. However, the majority of respondents surveyed in areas without a ban reported an overall average sales growth of nine percent.

“These findings suggest that bag bans may displace commerce and have real economic effects,” said NCPA senior fellow Pamela Villarreal. “Shoppers want to have a choice and will vote with their feet.”